1. Field
The disclosed concept relates generally to electrical switching apparatus and, more particularly, to electrical switching apparatus, such as circuit breakers. The disclosed concept also relates to movable contact arm assemblies for electrical switching apparatus.
2. Background Information
Electrical switching apparatus, such as circuit breakers, provide protection for electrical systems from electrical fault conditions such as, for example, current overloads, short circuits, abnormal voltage and other fault conditions.
Typically, circuit breakers include an operating mechanism, which opens electrical contact assemblies to interrupt the flow of current through the conductors of an electrical system in response to such fault conditions. The electrical contact assemblies include stationary electrical contacts and corresponding movable electrical contacts that are typically mounted on movable (e.g., pivotable) arms. The stationary and movable contacts are in physical and electrical contact with one another when it is desired that the circuit breaker provide electrical current therethrough to a load. When it is desired to interrupt the power circuit, the movable contact arm is pivoted, thereby moving the movable contact away from the stationary contact creating a space therebetween.
The movable contact arms of some circuit breakers are unitary members made from one single piece of material and including a first end, which cooperates with the circuit breaker operating mechanism (e.g., without limitation, operating handle), and a second end where the movable contact is disposed. Typically, the movable contact arms and movable contacts are made from copper. Thus, as the cost of copper increases, the cost of the movable contact arm assembly correspondingly increases.
There is, therefore, room for improvement in electrical switching apparatus, such as circuit breakers, and in movable contact arm assemblies therefor.